There are two general types of doughnut, cake doughnuts made from a mix with baking powder which produce a heavy dense product, and yeast raised doughnuts which are lighter and more spongy. Cake doughnuts are generally ring doughnuts, do not contain yeast and are not prooved during the manufacturing process; yeast raised doughnuts, on the other hand, are proofed, have a different texture, and are fluffier and lighter. Yeast raised doughnuts may be both ring type with icing, or shell type containing a filling.
Presently, yeast raised doughnuts are made by frying. The process illustrated in FIG. 1, generally comprises the following steps:    1. Mixing a dough mixture—containing, for example, wheat flour, dextrose, vegetable oil, salt, raising agents, emulsifiers, defatted Soya flour, whey powder, milk protein, skimmed milk powder, stabilizers, flavourings, colour and flour treatment agents—with yeast and water;    2. dividing into equal portions and allowing to ferment for up to 45 minutes during which time the dough rises to typically double in size;    3. kneading the dough either by machine or by hand so as to remove excess air, sheeting and shrinking the dough; and    4. cutting the dough into doughnut shapes.    5. The doughnut shapes are next transferred to a prooving room where heat and humidity are added for up to 45 minutes; in this specification a reference to ‘proving’ is to the addition of heat and humidity. A reference to a proven product shall be interpreted accordingly.    6. The doughnuts, now double in size are allowed to stand for up to 15 minutes creating a skin on the external surface of the doughnut.    7. The doughnuts are then fried for about 1.5 minutes or less in shortening at about 185° F.; and    8. after cooling the doughnuts are filled or iced or both.
Recently, as the public became more aware of the deleterious effect of fat in foods there has been an effort by the food industry to reduce the amount of fat in consumable products and a growing demand for healthier foods of all sorts including low fat equivalents of high fat foods. Doughnuts, in common with most fried foods, are seen as being high in fat and not suitable for a healthy diet. One way to avoid the high fat content of fried doughnuts is of course to avoid deep frying the dough and instead of frying, bake the doughnut.
A baked doughnut, however, would be expected by the skilled artisan to exhibit a bread-like texture lacking the external crispness and typical doughnut taste of the yeast raised deep fried doughnut.
In JP-A-3-127941, there is disclosed a method of manufacturing foodstuffs by baking while giving a flavour of fats or oils, i.e. a fried taste. The Japanese document discloses mixing a dough mixture of flour, yeast, sugar, eggs and seasoning with water; injecting the mixture in an automatic injector to form doughnut rings which are soft and deformable; pre-treating the rings at 100° C. on a net conveyor in an oven; spraying hot fat at 180° C. and baking at 190° C. Significantly, according to the disclosure, when a similar dough mixture was fried it did not survive the frying process. This reference does not disclose a process for making a raised yeast doughnut using a proven dough mixture but rather a very heavy, dense cake type doughnut product. Obviously the dough used is different from the standard yeast raised doughnut dough used by the industry to prepare fried doughnuts, because, as the patent indicates, this dough could not be fried.
GB 2015315 discloses a new moisture barrier applied to a fried doughnut.
WO-A-98/30105 discloses a glaze applied to a dough product which is to be frozen and in particular, a pizza. The glaze is applied to the dough product which is to be baked before freezing. The glaze consists of water, oil and a hydrophilic colloid. While this patent mentions doughnuts it provides no details with regard to a process for making a doughnut. In particular, there is no disclosure of a yeast raised doughnut. Instead it is clear that the process is generally applicable to bread based products. The skilled artisan would understand that the disclosed process which does not include a proving step, produces a product with a bread like texture rather than a yeast raised doughnut. There is no disclosure of a proven dough mixture coated with fat and then baked to produce a doughnut.
In view of the current trends to reduce the amount of fat in food products there is, therefore, still a need for a process that produces a raised yeast doughnut which maintains the texture and taste of a yeast raised fried doughnut with significant less fat content than the fried doughnut.